Adding HL7 version 3 data types to PostgreSQL

The HL7 standard is widely used to exchange medical information electronically. As a part of the standard, HL7 defines scalar communication data types like physical quantity, point in time and concept descriptor but also complex types such as interval types, collection types and probabilistic types. Typical HL7 applications will store their communications in a database, resulting in a translation from HL7 concepts and types into database types. Since the data types were not designed to be implemented in a relational database server, this transition is cumbersome and fraught with programmer error. The purpose of this paper is two fold. First we analyze the HL7 version 3 data type definitions and define a number of conditions that must be met, for the data type to be suitable for implementation in a relational database. As a result of this analysis we describe a number of possible improvements in the HL7 specification. Second we describe an implementation in the PostgreSQL database server and show that the database server can effectively execute scientific calculations with units of measure, supports a large number of operations on time points and intervals, and can perform operations that are akin to a medical terminology server. Experiments on synthetic data show that the user defined types perform better than an implementation that uses only standard data types from the database server.Comment: 12 pages, 9 figures, 6 table

Provably correct Java implementations of Spi Calculus security protocols specifications

Spi Calculus is an untyped high level modeling language for security protocols, used for formal protocols specification and verification. In this paper, a type system for the Spi Calculus and a translation function are formally defined, in order to formalize the refinement of a Spi Calculus specification into a Java implementation. The Java implementation generated by the translation function uses a custom Java library. Formal conditions on such library are stated, so that, if the library implementation code satisfies such conditions, then the generated Java implementation correctly simulates the Spi Calculus specification. A verified implementation of part of the custom library is further presente

Incorporating Security Behaviour into Business Models Using a Model Driven Approach

There has, in recent years, been growing interest in Model Driven Engineering (MDE), in which models are the primary design artifacts and transformations are applied to these models to generate refinements leading to usable implementations over specific platforms. There is also interest in factoring out a number of non-functional aspects, such as security, to provide reusable solutions applicable to a number of different applications. This paper brings these two approaches together, investigating, in particular, the way behaviour from the different sources can be combined and integrated into a single design model. Doing so involves transformations that weave together the constraints from the various aspects and are, as a result, more complex to specify than the linear pipelines of transformations used in most MDE work to date. The approach taken here involves using an aspect model as a template for refining particular patterns in the business model, and the transformations are expressed as graph rewriting rules for both static and behaviour elements of the models

Ontology-based semantic interpretation of cylindricity specification in the next-generation GPS

Cylindricity specification is one of the most important geometrical specifications in geometrical product development. This specification can be referenced from the rules and examples in tolerance standards and technical handbooks in practice. These rules and examples are described in the form of natural language, which may cause ambiguities since different designers may have different understandings on a rule or an example. To address the ambiguous problem, a categorical data model of cylindricity specification in the next-generation Geometrical Product Specifications (GPS) was proposed at the University of Huddersfield. The modeling language used in the categorical data model is category language. Even though category language can develop a syntactically correct data model, it is difficult to interpret the semantics of the cylindricity specification explicitly. This paper proposes an ontology-based approach to interpret the semantics of cylindricity specification on the basis of the categorical data model. A scheme for translating the category language to the OWL 2 Web Ontology Language (OWL 2) is presented in this approach. Through such a scheme, the categorical data model is translated into a semantically enriched model, i.e. an OWL 2 ontology for cylindricity specification. This ontology can interpret the semantics of cylindricity specification explicitly. As the benefits of such semantic interpretation, consistency checking, inference procedures and semantic queries can be performed on the OWL 2 ontology. The proposed approach could be easily extended to support the semantic interpretations of other kinds of geometrical specifications

An Experiment in Model Driven Architecture for e-Enterprise Systems

OMG's Model Driven Architecture demonstrates how a system's specification model can be used within the process of creating supporting software implementations. This article documents the findings of an experiment aimed at determining the extent to which this method of software engineering can be used within the domain of e-Enterprise systems